Rock dredging system and method

ABSTRACT

A dredge system, method, and apparatus, are provided that, according to one example embodiment of the invention, applies weight to a roller for dredging rock in a unique manner using the weight of a dredge unit that is supported by a floating support unit.

BACKGROUND

[0001] The present invention relates to dredging of hard materials, such as rock. In specific embodiments, the invention relates to systems and methods for dredging and transportation of dredging systems to dredging sites.

[0002] As shipping modernizes, the size of vessels has grown from ancient times. The trend continues today, as it is continually demonstrated that bulk shipment is more efficient. Many ports in the U.S. and overseas are more and more selectively competitive due to their ability to accommodate these larger vessels. The main factor in the ability to accommodate these vessels is water depth, or more accurately, the controlled depth of the main channels. In most cases, deepening of a channel is done by one of several means. Either by simply bucketing out the bottom formation, using a venturi-type suction pipe, or by employing a grinding machine on an extended arm, and then sucking up the cuttings. These technologies are quite effective on bottom types of sand, silt, mud, and clay. Various references showing devises and methods for dredging of hard and soft surfaces are seen in the following U.S. patents, all of which are incorporated herein by reference: U.S. Pat. Nos. 2,819,542; 3,171,220; 3,512,280; 4,037,874; 4,083,134; 4,204,347; 4,231,171; 4,357,764; 4,445,290; 5,778,568; and 6,318,005 B1.

[0003] A problem with all of these common technologies occurs when the bottom geology becomes too hard to cut or destroy. This is loosely defined as “rock” (e.g. material with a compressive strength in excess of about 500 p.s.i. and especially material with compressive strengths in excess of about 2500 p.s.i.). The current, most-used, technology for removal of rock is to drill holes, fill them with explosive, and blast larger holes. Then the rubble is bucketed out in a conventional manner. The resulting costs, safety issues, and environmental damage make this an unsatisfactory method. Therefore, there is a need for a system and method for dredging rock.

SUMMARY OF THE INVENTION

[0004] Problems associated with the systems described above are addressed by various example embodiments of the present invention. In one aspect of the invention, a dredge system is provided comprising: a dredge unit and a support unit; wherein the dredge unit and the support unit comprise, in combination: a launch mode and a dredge mode. In some further examples, a maintenance mode is also provided. In some examples, the launch mode comprises a connection between the dredge unit and the support unit in which the weight of the support unit is carried by the dredge unit. In one specific example, the connection comprises lift lines connected between the dredge unit and the support unit and/or protrusion and indentation combination to connect the support unit and the dredge unit. In many of the examples, the support unit, even in the launch mode, powers and controls the dredge unit.

[0005] According to another aspect of the invention, an apparatus for dredging under the surface of the water (for example, a dredge unit) is provided. The apparatus comprises: a cylinder having an outer surface and an axis; a frame holding the cylinder in a rotating arrangement about the axis; and a motor connected to the frame to rotate the cylinder about the axis. The weight applied to the cylinder comprises the weight the of frame and submerged equipment connected to the frame. In a specific example, steerable tracks are connected to the frame fore and aft of the roller. In still another example, a floating support vessel (e.g., a support unit) is attached to the motor with power supply and control connections, and lift lines are connected between the frame and the support vessel.

[0006] According to yet another aspect of the invention, a system for dredging rock located under the surface of a body of water is provided. The system comprises: means for engaging the rock with a roller, means for applying, under the surface of the water, weight to the roller, means for turning the roller, and means for controlling the roller direction. The means for controlling is located under the water. In one example, means is also provided for driving the roller through direct mechanical engagement with the rock.

[0007] According to one specific embodiment, the roller comprises means for cutting (e.g., cutting teeth mounted in a substantially helical and cylindrical pattern). According to an alternative embodiment, the roller comprises a means for grinding (for example, grinding teeth mounted). In still other specific embodiments, the roller comprises a unitary roller or a multipiece roller. In still further embodiments, the “roller” or “cylinder” comprises a set of teeth (either for grinding or cutting mounted in a manner in which a substantially cylindrical, although not smooth, shape is defined by the teeth. As used herein, “grinding” is used in its most general manner, including percussive action, chipping action, etc.

[0008] In yet a further example embodiment, the means for engaging comprises a frame supporting the roller; the means for applying comprises the weight of the roller and the frame; the means for controlling comprises steerable track units; and the means for turning the roller comprises a motor mounted on the frame. In a further example, the means for applying further comprises additional weight applied to the roller through the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a perspective view of an example embodiment of the invention.

[0010]FIG. 2 is a side view of an example embodiment of the invention.

[0011]FIG. 3 is a top view of an example embodiment of the invention.

[0012]FIG. 4 is a perspective view of an example embodiment of the invention.

[0013]FIG. 5 is a side view of an example embodiment of the invention.

[0014]FIG. 6 is a top view of an example embodiment of the invention.

[0015]FIG. 7 is a perspective view of an example embodiment of the invention.

[0016]FIG. 8 is a perspective view of an example embodiment of the invention.

[0017]FIG. 9 is a perspective view of an example embodiment of the invention.

[0018]FIG. 10 is a side view of an example embodiment of the invention.

[0019]FIG. 11 is a side view of an example embodiment of the invention.

[0020]FIG. 12 is a side view of an example embodiment of the invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

[0021] Referring now to FIG. 1 an example embodiment of the invention is seen in which reversible roller 10 rotates in either direction about axis 18 pressing engagement members 16 (for example, teeth, cutters, and blades) into rock 14. As roller 10 causes engagement member 16 to break away portions of rock 14, the interaction between roller 10 and mandrel 12 causes broken pieces (not seen) to move up under mandrel 12 to chute 20 or down, under, and behind mandrel 12. The removal of the pieces through chute 20 will be described in more detail below.

[0022] Referring now to FIG. 2, an example support system around roller 10 is seen. According to the illustrated embodiment, roller 10 is supported and forced into the formation by axle 18 by bearing yoke 22 which is connected to frame 24. Also connected to frame 24 are yokes 26 which support track units 28. Mandrel 12 is supported by mandrel connection members 30 from frame 24. The illustrated system is driven by drive units 32 on track units 28. According to one example embodiment, drive units 32 drive wheels 34 through chains 36. In alternative embodiments, drive units 32 comprise direct geared drives, belt drives, and other means for driving wheels. Wheel 34 drives track 38 from the interaction of chain 36 and sprocket 40. Drive units 32 in the illustrated embodiment comprise hydraulic drive units driven by hydraulic drive lines 42 which connect to hydraulic power supply unit 44 and are supplied by umbilical 46. Hydraulic supply 44 also includes a hydraulic motor (not shown) which is powered through umbilical 46 to drive driveshaft 48. Transmission 50 is powered by driveshaft 48 to turn transmission sprocket 52 which, in turn, drives chain 54 to turn roller 10 through roller sprocket 56. In alternative embodiments, transmissions 50 drives a hydraulic motor mounted in direct-drive connection with axel 18, eliminating the sprockets and drive chains. Other means for turning or driving axel 18 include drive belts and other means for turning axels and wheels, whether electric, hydraulic, or otherwise.

[0023] Roller 10 rotates about axle 18 in a counter-clockwise direction as the system moves forward into rock 14. The system is steered through a pivot 58 incorporated into aft yoke 26 for pivoting aft drive unit 32. In alternative embodiments, Tone yokes 26 include pivots to allow for independent control of tone drive units 32.

[0024] In the illustrated example, it is the weight of the system that provides the pressure for the dredging operation; extension booms and/or downward force from a floating platform is not needed. In alternative embodiments, weights, in addition to the weight of the frame and any housing surrounding the frame, are added. Other systems which are useful as alternative example embodiments of the invention, when adapted for use under a body of water (as opposed to small creeks or puddles through which such systems are driven while removing rock) under-water use, include many of those seen in the following U.S. patents, all of which are incorporated herein by reference: U.S. Pat. Nos. 5,382,084 and 5,639,180.

[0025] Referring now to FIG. 3, a top view of the system seen in FIG. 2 is shown in which aft drive units 32 reside below frame 24 on frame cross-members 62 and 64. Forward drive units 32, likewise, reside on frame cross-members 66 and 68, and on 66 and 70, respectively. Also seen in FIG. 3, differential 72 connects driveshaft 48 to transmission 50 and sprocket 52.

[0026] Referring now to FIG. 4, an example embodiment is seen in which chute 20 and mandrel 12 collect broken material to be removed through flanged connection 80 to the surface through a surface connection (not shown). Water supply 82 is connected to manifold 84 to which flush lines 86 are also connected. Flush lines 86 provide flushing water the length of mandrel 12. Manifold 84 is also connected to flush lines 88 which are, in turn, connected to chute 20 for supplying further flushing water as an aid for lifting the material removed by roller drum 10 through the use of engagement members 16. Also connected to manifold 84 is eductor jet-line 90 which, in turn, is connected to eductor jets mounted in flange connection 80 (not shown).

[0027] Referring now to FIG. 5, the roller 10 is seen connected to its frame and housing (generally shown by a box) in engagement with rock 14. The frame unit supporting roller 10 is connected to a vessel 91 floating at water surface 93 and is connected by lifting lines 97. In operation, lifting lines 97 lift and lower the roller system, and are used to take partial weight off the system, dependant on the conditions encountered. Umbilical 46 and water supply lines 82 are illustrated along with an effluent line 95 which is connected to flange connector 80 of FIG. 4 for removing material broken from rock 14 to vessel 91.

[0028] Referring now to FIG. 6, an example embodiment of support unit vessel 91 is seen. Four barges 91 a-91 d are connected by rigid connections 100 (seen best in FIG. 9). Main engine 102 is positioned on barge 91 a and includes hydraulic power supply 102 h, both of which are controlled by control house 104. Control house 104 further controls water jet pumps 106 a-106 c. Pumps 106 a-106 c and hydraulic supply 102 h are connected through connector lines 108 to umbilical junction 110 which is, in turn, connected to umbilical 46. The dredge unit with roller 10 is seen in dashed lines, attached to barges 91 b and 91 d by lifting lines 97. Lifting lines 97 are attached to wenches (not shown) at masts 99 a-99 d. Effluent line 95 is connected to shale-shaker screen 120 mounted on barge 91 c. Shale-shaker screen 120 is attached to conveyor 122 for transport of cuttings onto cuttings dump-barge 130. Shale-shaker screen 120 is also connected to water return line 123 for recycling of water through pumps 106 a-106 c.

[0029] Referring now to FIG. 7, a more specific example of roller 10 mounted on axle 18 is seen. According to the illustrated example, roller 10 comprises a cylindrical shape having an axial length greater than its diameter and an end cap 170 through which axle 18 passes. Also seen in FIG. 7 is a tang 172 extending from axle 18, which locks roller 10 to axle 18.

[0030] Referring now to FIG. 8, an alternative embodiment of roller 10 is seen in which roller 10 comprises roller segments 10 a-10 c. According to the example in FIG. 8, each of segments 10 a-10 c has an axial length which is greater than the spacing between the next subsequent roller segment resulting in an effective unitary roller 10 made from such segments. In some embodiments, segments 10 a-10 c are in physical engagement with each other, and in alternative embodiments, segments 10 a-10 c are spaced apart, as show in FIG. 8.

[0031] As seen in FIG. 4, engagement members 16 are arranged in a helical pattern such that when roller 10 is rotated in the roll direction indicated in FIG. 4, the effluent is moved toward the center of mandrel 12 so that it is removed by chute 20. In some embodiments, an auger is connected to chute 20 to lift the material removed by the roller 10. In other embodiments, a conveyor is used, connected to chute 20. In many embodiments, suction and/or fluid circulation is used, either alone or in combination with an auger, conveyor or other mechanical lifting means. In one example embodiment of the invention, the roller drum 10 is made in two segments wherein the helical pattern on one side comprises one segment and the helical pattern on the other side of drum 10 comprises the reverse pattern.

[0032] According to a further embodiment of the invention, the dredge unit and the support unit are arranged to be assembled on land, lifting their own floatation and driving the entire support flotation and dredge assembly into the water. As seen in FIG. 9, in one example embodiment, vertical supports 92 and 92′ are attached to barge 91 b, and supports 94 and 94′ are connected to barge 91 d. Cross pieces 96 and 96′ are connected between supports 92-94 and between 92′ and 94′, respectively. The support system for roller 10 (an example of which is discussed above with reference to FIG. 4), is not shown. However, according to the illustrated embodiment, the support system is attached to supports 92-96 and 92′-96′ via cables 97 (FIG. 5) and, in one mode, to protrusions 98, located on the sides of barges 91 b and 91 d.

[0033] Referring now to FIG. 10, the example of FIG. 9 is seen in a side-view. The support system for roller 10 is seen retracted and covered by marine mill system housing 135. Housing 135 extends below barge 91 d where track units 28 and roller 10 are seen. The support system and housing 135 are connected to barges 91 b and 91 d through locking receptacles (not shown) that mate with protrusions 98 (FIG. 9). Housing 135 is raised and lowered by (or raises and lowers, depending on the environment) barge assembly 91 via cables 97 (FIG. 5) that are attached to housing 135 and run over supports 96 and 96′. Cables 97 are operated by winches (not shown) located on barges 91 a and 91 c. The winches are powered through main engine 102 and controlled through control house 104.

[0034] The mode shown in FIG. 10 is a “land travel” mode and/or a “launch” mode in which the weight of barge 91 is carried by the tracks 28 through the connections described above.

[0035] In order to assemble the system into the launch mode, the support system, surrounded by housing 135, and one assembly embodiment, is used on a relatively soft surface (such as a beach) to excavate a trench into which housing 135 is placed. Such excavation is done using power coupling to motor 102 on barge 91 a (which is also resting on the beach). Alternatively, the trench is excavated with other means (for example, traditional heavy equipment). Barges 91 a-91 d are then assembled around housing 135; lifting lines 97 and other control and power lines are also connected. Appropriate load-bearing connections are made between barges 91 b and 91 d to housing 135. At this point, the entire weight of the assembled barge 91 is held by housing 135. Tracks 28 are then used to move the assembled system into the water. In an alternative embodiment, no trench is excavated. The barges 91 a-91 d are assembled around housing 135, and lifting lines 97 (FIG. 5) are used to lift the barge assembly to an appropriate position for travel (for example, by running lifting lines 97 through reversing pulleys).

[0036] Once the system illustrated in FIG. 10 is afloat, it is, according to one embodiment, towed to the location where the dredging operations are to be performed. At that point, as seen in FIG. 11, housing 135 is lowered by lines 97, and locking receptacles 98′ are seen in housing 135 for mating with protrusions 98 (FIG. 9). In operation, track units 28 pull housing 135 along the bottom and barge 91 follows through the tension in lines 97. In alterative embodiments, barge 91 is supplied with its own station-keeping motors and/or motors for self-propulsion.

[0037] Referring now to FIG. 12, an afloat maintenance mode is seen in side-view in which barge 91 d has been removed from the drawing for illustrative purposes. Housing 135 is raised by lift lines 97 to a position in which the support system illustrated in FIG. 2 is accessed.

[0038] The above embodiments are given by way of example only. Other examples will occur to those with ordinary skill in the art without further elaboration upon review of the present disclosure. It is intended that the specification and specific examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims. 

What is claimed is:
 1. A method of dredging rock located under the surface of a body of water, the method comprising: engaging the rock with a roller, applying, under the surface of the body of the water, weight to the roller, turning the roller, and controlling the roller from above the surface of the water.
 2. A method as in claim 1 further comprising driving the roller through direct mechanical engagement with the rock.
 3. A method as in claim 1 wherein the engaging comprises cutting.
 4. A method as in claim 1 wherein the engaging comprises grinding.
 5. A system for dredging rock located under the surface of a body of water, the system comprising: means for engaging the rock with a roller, means for applying, under the surface of the body of water, weight to the roller, means for turning the roller, and means for steering the roller direction, wherein the means for steering is located under the water.
 6. A system as in claim 5 further comprising means for driving the roller through direct mechanical engagement with the rock.
 7. A system as in claim 5 wherein the roller comprises means for cutting.
 8. A system as in claim 7 wherein the means for cutting comprises teeth mounted on the roller in a helical pattern.
 9. A system as in claim 5 wherein the roller comprises a unitary roller.
 10. A system as in claim 5 wherein the roller comprises a multipiece roller.
 11. A system as in claim 5 wherein the roller comprises means for grinding.
 12. A system as in claim 11 wherein the means for grinding comprises grinding teeth.
 13. A system as in claim 5 wherein the means for engaging comprises a frame supporting the roller.
 14. A system as in claim 5 wherein the means for applying comprises the weight of the roller and the frame.
 15. A system as in claim 14 wherein the means for applying further comprises additional weight applied to the roller through the frame.
 16. A system as in claim 5 wherein the means for turning the roller comprises a motor mounted on the frame.
 17. A system as in claim 5 wherein the means for steering comprises steerable track units.
 18. An apparatus for dredging under the surface of the water comprising: a cylinder having an outer surface and an axis, a frame holding the cylinder in a rotating arrangement about the axis, a motor on the frame connected to rotate the cylinder about the axis, wherein the weight applied to the cylinder comprises the weight the of frame and submerged equipment connected to the frame.
 19. An apparatus as in claim 18, further comprising steerable tracks connected to the frame fore and aft of the roller.
 20. An apparatus as in claim 19, further comprising a support floating vessel attached to the motor with power supply and control connections.
 21. An apparatus as in claim 20 further comprising lift lines connected between the frame and the support vessel.
 22. A dredge system comprising: a dredge unit and a support unit, wherein the dredge unit and the support unit comprise, in combination: a launch mode and a dredge mode.
 23. A dredge system as in claim 22 further comprising a maintenance mode.
 24. A dredge system as in claim 22 wherein the launch mode comprises a connection between the dredge unit and the support unit in which the weight of the support unit is carried by the dredge unit.
 25. A dredge system as in claim 24 wherein the connection comprises lift lines connected between the dredge unit and the support unit.
 26. A dredge system as in claim 24 wherein the connection comprises protrusion and indentations connecting the support unit and the dredge unit.
 27. A dredge system as in claim 22 wherein the support unit, in the launch mode, powers and controls the dredge unit. 